Republicans eager to dislodge Donald Trump from his perch at the top of primary polls showed new willingness to directly confront the real estate magnate Wednesday, questioning his temperament, his authenticity as a political outsider and his conservative bona fides during a critical pair of debates at the Reagan Presidential Library on Wednesday.

For one-time front-runner Jeb Bush, that meant going toe-to-toe with Trump over his business record while portraying himself as a “steady hand.”

For Wisconsin Gov. Scott Walker, who spiked in early polling but fell to earth as Trump took off, it meant highlighting his successful battles with labor unions while rebutting the Democratic talking points he said Trump had borrowed.

“We don’t need an apprentice in the White House,” he said to Trump, in a jab at Trump’s old TV show. “We need someone who can actually get the job done.”

And for Carly Fiorina, the former business executive who graduated to the main debate after a shining performance in last month’s undercard forum, it meant dismissing Trump as “an entertainer” while positioning herself as someone who could withstand the grind of a national campaign.

Trump seemed to nod toward humility in an opening statement eschewing a “braggadocious” style, but he quickly reverted to form. Trump zinged Kentucky Sen. Rand Paul over his low poll numbers after Paul called him “sophomoric,” and he noted that Walker went “down the tubes” in Iowa.

At one early point, as he and Bush sparred, Trump tweaked his rival by acknowledging Bush’s newly aggressive approach: “More energy tonight. I like that.”

The good news for the sprawling cast of Republican presidential contenders running in Trump’s shadow is that the debates in Simi Valley offered a chance to make their cases before a television audience likely in the tens of millions.

But for as many as a dozen of them, Wednesday also emerged as a critical test of viability. The stakes were high for once-touted contenders who have been upstaged by political outsiders, and others were forced to try to demonstrate they still belonged on stage at all.

Former Texas Gov. Rick Perry, the leader of the second tier a month ago, dropped out of the race Friday in an ominous sign for others ahead of a key fundraising deadline at month’s end.

The urgency of confronting the Trump challenge was clear immediately in a preliminary debate among four GOP hopefuls lagging in the polls, where he and the immigration issue that he’s seized on dominated early.

“The best way for us to give this election back would be to nominate a Donald Trump,” Louisiana Gov. Bobby Jindal charged. “He’ll implode in the general election.”

In the main debate, on a stage crowded with 11 candidates, Trump was center, both literally and figuratively. To one side of him was Dr. Ben Carson, another surging candidate who has confounded race handicappers. He highlighted his personal story and outsider status with a much softer tone than Trump’s.

“When I entered this race, all the political pundits said it’s impossible,” he said. “But the pundits forgot about one thing, and that is the people. And they are really in charge.”

The debates, staged before the blue and white Air Force jet that Ronald Reagan flew in as president, revealed the extent to which the Gipper’s political party has broken with him in practice, even as many continued to speak reverently of him. Reagan signed a major immigration reform bill during his two terms, and even openly referred to the policy as “amnesty,” for instance.

South Carolina Sen. Lindsey Graham, one of the co-sponsors of a comprehensive immigration reform plan that passed the Senate in 2013, challenged others on immigration during a well-reviewed performance where he flashed a self-effacing sense of humor.

“In my world, Hispanics are Americans,” he said.

Bush also used immigration to challenge Trump directly, contrasting what he said was the Reagan-style optimistic approach with “the Trump approach that says that everything is bad.” He demanded Trump apologize to his wife, a Mexican-American, for invoking her during the campaign. Trump declined to do so, insisting he had done nothing wrong.

When Fiorina took Trump on, it was when asked to respond to Trump’s disparaging remark over her appearance. “I think women all over the country heard very clearly what Mr. Trump said,” she said.

By necessity more than by choice, the candidates also broke the so-called “11th Commandment” long attributed to Reagan _ that thou shalt not speak ill of a fellow Republican. CNN’s Jake Tapper, the lead questioner Wednesday, delivered on his pledge to stir the pot among the candidates themselves to seek more direct clashes.

But some strategically stayed out of the fray.

“If I were sitting at home and watch thing back and forth, I would be inclined to turn it off,” Ohio Gov. John Kasich said. “I mean, people at home want to know across this country, they want to know what we’re going to do to fix this place.”

(Mehta reported from Simi Valley and Memoli from Washington. Staff writer Lisa Mascaro in Washington contributed to this report.)

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